A known switching element of this kind is disclosed in U.S. Pat. No. 4,524,256. It comprises, as a movable electrode, a contact-mesh, said contact-mesh consisting exclusively of metallic wires which extend undulated in both weaving directions. This contact-mesh is embedded in an elastic insulating layer which rises above the bare wave crests, thereby keeping them in distance of an adjacent flat electrode. Upon compressing said insulating layer the wave crests of the wires are moved to the surface of the insulating layer, thereby contacting said flat electrode. As soon as the compression is stopped, the resetting forces of the elastic insulating layer make the contact-mesh to move into its original position in distance of the flat electrode.
Manufacture of this switching element is relatively expensive. A foamed material is used as the insulating layer. After embedding the contact-mesh, the insulating material is to be mechanically removed down to the surface of the fabric. Thereafter, the insulating material is foamed by heat-treatment in order to uncover the wave crests and to increase the effective thickness of the insulating layer as compared with the fabric thickness. A further disadvantage of the insulating layer is that its elasticity may decrease due to aging, thereby altering the pressure-sensitivity and imparing the function of the switching element.
Another switching element, fundamentally based on the same principles, is described in the publication DE-A1-34 24 060. The wires of the contact-mesh are provided with an insulating layer which is to be removed at the wave crests. For this, a chemical process is proposed which is to be applied after the mechanical removal of the elastic insulating material. By this additional process step the manufacturing expenses are further increased.